The role of the ACHEM core is to provide expertise and services in the diverse fields of small molecule identification by molecular spectroscopy and species characterization using electron microscopy. In the former area, the investigators have all the routine tools for characterization of pure organic compounds by proton and carbon NMR, and mass spectroscopy. This sort of analysis is prerequisite to any organic synthesis effort, and is a requirement for structure elucidation of any newly isolated marine natural products such as toxins from Pfiesteria or freshwater cyanobacteria that Center investigators will be studying in the next grant period. They also support a broadly interdisciplinary effort in tracing the metabolic fate of ammonia in gulf toadfish using isotope ratio mass spectroscopy, and characterization of algal species using electron microscopy. Major, shared instrumentation in the AChEM Core includes three high-field superconducting NMRs, four mass spectrometers, and two electron microscopes. The combined cost of the instruments in this Core is several million dollars. They were all acquired through shared-instrumentation grants from NSF and NIH, with University cost share always exceeding agency guidelines. Their operation and maintenance is largely borne by the university. The Center makes only a nominal contribution to the maintenance costs for these instruments, and pays for beam time on the electron microscopes.